Clothes washer with improved turbine type pump



J. BOCHAN 3,127,840 CLOTHES WASHER WITH IMPROVED TURBINE TYPE PUMP April7, 1964 2 Sheets-Sheet 1 Filed Dec. 26, 1961 2 m B s Q m u 5 mm 4. NH mM 1 B W O D D Q 0 o 0 0 N H o o o 1 O o o o o I m 4 o o o o 0 4r... Y I5 o o o B o o o o m o H H I B 5 f I F 2 M I l B m I7. G v 1 2 I F 4% o oo m m a a. o o 1 a xhm o o I 0 o 4 7 O 0 MW 2 r0 0 Z 3 2 o o 3 8 4 o S 59 a a 5 4 a I 4 5 Id m k 4 a 3 r r w. w.

ms ATTORNEY J. BOCHAN A ril 7, 1964 CLOTHES WASHER WITH IMPROVED TURBINETYPE PUMP 2 Sheets-Sheet 2 Filed Dec. 26, 1961 F'IG.2

INVENTOR. J'OHN BOCHAN BY w P M F-IGA 4 w HIS ATTORNEY United tatesPatent Orifice 3,127,840 Patented Apr. 7, 1964 3,1273% CLUTHES WASHERWITH HMlROVEi) TUREFLNE TYPE PUMP John ffinehan, Louisville, K n,assignor to General Company, a corporation of New York Filed Dec. as,19-61, See. No. 162,922 4 Claims. (Cl. l033) This invention relates tolaundry apparatus such as clothes washing machines, and moreparticularly to an improved pump for use in such machines.

Automatic clothes washing machines virtually always include a drain pumpwhich is put into operation in order to effect draining of liquid fromthe machine after washing and rinsing operations. This pump is generallyoperated by the same power source, usually an electric motor, whichoperates the washing system of the machine so that the motor willalternatively provide a washing action in the machine or serve to drainliquid out of the machine. An additional function which has beenprovided in several commercially available washing machines in recentyears is recirculation of the wash liquid during the washing operation,usually for filtering purposes.

Various factors, including the ability to pass small rigid articlescarried out by wash water, durability, serviceability, and the like haveled to a general trend in the washing machine industry to utilizeturbine type pumps for the removal of the liquid from the machine, asopposed to centrifugal type pumps. it is well known that, with a turbinetype pump, direction of flow through the pump can be reversed simply byreversing the rotation of the pump impeller, as opposed to centrifugaltype pumps wherein flow necessarily is always in a generally radiallyoutward direction through the pump. in the concurrently filedapplication Serial No. 158,288 or" James M. Pindcr, filed December ll,1961, assigned to the assignee of the present invention, there isdisclosed and claimed a turbine type pump which elfects, by reversingthe impeller rotation, both the water recirculation function during thewashing and rinsing operations, and the draining operation during liquidextraction operations. While the pump of the Finder application isoperative as disclosed, the flow rate tends to be somewhat low becauseof the tendency of such a dual-purpose pump to air lock upon reversaland thus provide a less effective pumping action. This, in turn,decreases the recirculation flow and also requires a longer drainingtime, both of which are aspects tending to affect, to some degree,marketability of machines including such a structure.

It is therefore an object of my invention to provide an improved singleimpeller turbine pump formed so as to pump with high efliciency fromdifferent inlets to different outlets when the impeller rotates inopposite directions.

A further object of my invention is to incorporate such a pump in anovel manner in a washing machine so as to provide thereby, with fulleffectiveness, recirculation of the liquid during washing and rinsing,and draining of the liquid during liquid extraction.

A further object of my invention is to achieve a structure wherein thesand and other heavy soils removed from clothes will tend to be removedby the pump during draining operations but will tend to pass to aposition where they are not moved by the pump during recirculationoperations. Yet a further specific object of my invention is to providean improved turbine type pump having an impeller formed to providegreater flow and pressure in one direction of rotation than in theother.

Briefly stated, in accordance with one aspect of my invention I providea turbine pump wherein the housing, with a substantially annular outerwall joined by suitable bottom and top closing walls, definestherewithin a substantially toroidal pump chamber. in this chamber thereis a rotatable impeller which has an annular series of blades extendingoutwardly, so that during rotation of the impeller the blades have aturbine effect on liquid in the chamber tending to pump it in one or theother direction depending upon the direction of rotation of theimpeller. The outer wall has first and second circumferentially spacedoutlet openings formed therein, and the top wall also has first andsecond circumferentially spaced inlet openings formed therein. Eachinlet opening is circumferentially spaced in relation to its associatedoutlet opening so that liquid may be pumped from one of the inletopenings to one of the outlet openings depending upon the direction ofrotation of the impeller. To insure that the liquid passes out throughthe appropriate outlet opening, a dam is positioned in the chamberbetween the outlet openings.

I propose to provide this type of pump with the inlet openings both beinconnected to receive liquid from the liquid receptacle of a washingmachine. One of the outlets is connected so that it causes recirculationand the other outlet is connected so that it is connected to a drain.Thus, when the impeller is rotated in one direction liquid pmses fromthe receptacle into the pump and is recirculated back into thereceptacle, and when rotation of the impeller in the other directionoccurs, the liquid passes from the washing machine receptacle out todrain.

The subject matter which I regard as my invention is particularlypointed out and distinctly claimed in the concluding portion of thisspecification. The invention itself, however, both as to itsorganization and method of operation, together with further advantagesthereof, may best be understood by reference to the followingdescription taken in conjunction with the accompanying drawings.

in the drawings, FIGURE 1 is a side elevational view of a clotheswashing machine including my novel pump, the view being partially brokenaway and partially in section to illustrate details;

Pi URE 2 is a partially sectionalized plan view of the pump of myinvention;

FIGURE 3 is a view along line 33 in FIGURE 2; and

FIGURE 4 is a View along line 4-4 in FIGURE 2.

Referring now to FIGURE 1, I have shown therein an agitator type clotheswashing machine 1 having a conventional basket or clothes receivingreceptacle 2 provided over its side and bottom walls with perforations 3and disposed within an outer imperforate tub or casing 4. The basket 2may be provided with a suitable clothes retaining member 5 forpreventing clothes from being floated over the top of the basket, andwith a balance ring 6 to help steady the basket when (as will beexplained) it is rotated at high speed.

Tub 4 is rigidly mounted within an appearance cabinet 7 which includes acover 8 hingedly mounted in the top portion 9 of the cabinet forproviding access to an opening 1% of the basket 2. As shown, a gasket 11may be provided so as to form a seal between the top of tub 4 andportion 9 of the cabinet thereby to prevent escape of moisture and moistair into the cabinet around the tub. The rigid mounting of tub 4 withinthe cabinet 7 may be effected by any-suitable means. As a typicalexample of one such means, I have provided strap members 32 each ofwhich is secured at one end to an inturned flange 13 of the cabinet andat its other end to the outside of tub 4. At the center of basket 2there is positioned a vertical axis agitator 14 which includes a centerpost 15 and a plurality of curved water circulating vanes 16 joined attheir lower ends by an outwardly flared skirt 17. Both the clothesbasket 2 and the agitator 14 are rotatably mounted. The basket ismounted on the flange 18 of a rotatable hub 19 and the agitator 14 ismounted on a shaft (not shown) which extends upwardly through the hub 19and through the center post and is secured to the agitator so as todrive it.

During the cycle of operation of the machine 1, water is introduced intothe tub 4 and basket 2, and the agitator 14 is then oscillated back andforth on its axis, that is, in a horizontal plane within the basket towash the clothes therein. Then after a predetermined period of thiswashing action, basket 2 is rotated at high speed to extractvcentrifugally the washing liquid from the clothes and to discharge itto drain. Following this extraction operation, a supply of clean liquidis introduced into the basket for rinsing the clothes and the agitatoris again oscillated. Finally the basket is once more rotated at highspeed to extract the rinse water.

The basket 2 and agitator 14 are driven through suitable means from areversing motor 2th through a drive including a clutch 21 mounted on themotor shaft. Clutch 21 may conventionally allow the motor to startwithout a load and then accept the load as it comes up to speed. Asuitable belt 22 transmits power to a transmission assembly 23 through apulley 24. Thus, depending upon the direction of motor rotation, thepulley 24 of transmission 23 is driven in opposite directions.

Conventionally, transmission clutch 21 may be formed as a two-speedclutch so as to provide various operating speeds for the machine, and inthis connection a solenoid member 25 having a plunger 25 which operatesa control member 27 through spring 28 is provided in order to achievethe two-speed operation. Specifically, when solenoid 25 istie-energized, the clutch 21 provides a direct drive between motor 26and pulley 24, and when solenoid 25 is energized clutch 21 provides areduced speed drive to pulley 24. A two-speed clutch of this type,particularly suited for use in the illustrated machine, is described indetail and claimed in my Patent 2,869,699 issued on January 20, 1959,and assigned to General Electric Company, assignee of the presentinvention.

The transmission 23 is so arranged that it supports and drives both theagitator drive shaft and basket mounting hub 19. When motor 24) isrotated in one direction the transmission causes agitator 14 tooscillate in a substantially horizontal plane within the basket 2.Conversely, when motor 2t) is driven in the opposite direction, thetransmission rotates the wash basket 2 and agitator 14 together at highspeed for centrifugal liquid extraction. While the specific type ofdriving mechanism used does not form part of the invention, reference ismade to Patent 2,844,225, issued to James R. Hubbard et al. on July 22,1958, and owned by the General Electric Company, assignee of the presentinvention. That patent discloses in detail the structuralcharacteristics of a transmission assembly suitable for use in theillustrated machine.

In addition to operating the transmission 23 as described, motor 20 alsoprovides a direct drive through a flexible coupling 29 to a pumpstructure generally indicated at 30 which forms an important part of myinvention. As will be more fully explained herebelow, pump St) has ahousing 31 with an upper surface formed with liquid inlets communicatingwith the bottom of tub 4. Pump 30 also has a pair of outlets 32 and 33;outlet 33 communicates through a conduit 34 with a suitable drain (notshown) and outlet 32 communicates with a conduit 35 which in turn leadsto a nozzle 36. As will be explained, When motor 20 rotates in thedirection to cause spinning of basket 2, pump 30 discharges liquid fromtub 4 to outlet 33 and thence to drain, and in the other direction ofmotor rotation (in which agitation is provided) the pump dischargesliquid from tub 4 through outlet 32 and then through conduit 35 andnozzle 36.

Nozzle 36 is positioned to discharge into a filter pan 37 secured on thetop portion 38 of agitator 14 so as to be movable therewith. With thisstructure then, when the motor is rotating so as to provide agitation,pump 30 draws liquid from tub 4 and discharges it to conduit 35 so thatthe liquid passes from nozzle into filter pan 37 and then down through anumber of small openings provided in the bottom or" the filter pan andback into basket 2. In this manner, the filter pan 3'7, together withits small openings 39 and its upstanding side wall 40, causes lint whichis separated from the clothes during the washing 0 eration to befiltered out of the water and thus prevents it from being redeposited onthe clothes. This type of structure is more fully described and claimedin Patent 2,481,979, issued to Russell H. Colley on September 13, 1949,and assigned to General Electric Company, owner of the presentinvention.

The motor 2t), clutch 21, transmission 23, basket 2 and agitator 1 forma suspended Washing and centrifuging system which is supported by thestationary structure of the machine (which includes tub 4) so as topermit isolation of vibrations from the stationary structure; it will beunderstood that such vibrations occur primarily as a result of highspeed spinning of basket 2 with a load of clothes therein as mentionedabove. While any suitable suspension structure may be used, one suchstructure may, for instance, include a bracket member 44 withtransmission 23 mounted on top thereof and motor 26 mounted to theunderside thereof. The bracket member in turn is secured to upwardlyextending rigid members 45, and each of the two upwardly extendingmembers 4-5 is connected to a cable 46 supported from the top of themachine. While only a portion of the suspension system is shown inFEGURE 1 of the drawings, such a vibration isolating system is fullydescribed and claimed in my Patent 2,987,196 issued on lune 6, 1961, andassigned to the General Electric Company, assignee of the presentinvention.

ln order to accommodate the movement which occurs between basket 2 andtub 4 without any danger of leakage between them, the stationary tub 4is joined to the upper part of transmission 23 by a suitable boot member47. Boot 47 may be of any suitable configuration, many of which areknown in the art, to permit relative motion of the parts to which it isjoined without leakage therebetween.

Completing now the description of the machine as illustrated in FIGURE1, hot and cold water may be supplied to the machine through conduits 48and 49 which are adapted to be connected respectively to sources of hotand cold water (not shown). Conduits 48 and 49 extend into aconventional mixing valve structure 5d having solenoids 51 and 52, sothat energization of solenoid 511 permits passage of hot water throughthe valve to a hose 53, energization of solenoid 52 permits passage ofcold water through the valve, and energization of both solenoids permitsmixing of hot and cold Water in the valve and passage of warm water intohose 53. Hose 53 has an outlet 54 positioned to discharge into basket 2so that when one or both of the solenoids 51 and 52 is energized waterenters into basket 2 and tub 4.

The level to which the Water rises in the basket and tub may becontrolled by any suitable means. One typical means of doing this is toprovide an opening 55 in the side of tub 4 adjacent the bottom thereof,the opening 55 being connected through a conduit 56 and a tube 57 to aconventional pressure sensitive device (not shown) which mayconventionally be positioned within the backsplasher 53 of machine 1.With such devices, as the water rises in basket 2 and tub 4 it exertsincreasing pressure on the column of air trapped in tube 57; at apredetermined pressure level the column of air then trips the pressuresensitive mechanism to shut oii whichever of solenoids 51 and 52 may beenergized and start the agita t-ion which is provided during the washingand rinsing steps as described above.

Referring now to FlGURES 2, 3, and 4 in conjunction with FIGURE 1, pumpSti has a housing which is made up of an upper member 59 and a lowermember 6%) provided with mating peripheral flanges secured together by anumber of threaded members 61. In effect, the two members provide anupper wall 62 and a lower wall 63 which are joined by an annular outerWall 64 so as to form a substantially torodial pump chamber 65.

The previously mentioned outlets '32 and 33 communicate with chamber 65through the annular outer wall 64, and a dam 66 is positioned in chamber65 between the two outlets. The dam 66 substantially blocks the chamber65' between the outlets, leaving, however, enough room for the unimpededrotation of the blades 67 of an impeller 68 which is positioned so as(to have its blades 67 extending substantially radially outwardly intothe pump chamber as shown. The positioning of the impeller 68 may beeffected in any desired manner. For instance, the impeller may bemounted on a shaft 69 which passes through a seal 70 (FIGURE 3) and thenextends downwardly into engagement with the flexible coupling 29mentioned in connection with FIGURE 1. The clearances of the impeller,as it rotates within the space provided for it, are relatively narrow sothat there will be little leakage from .the chamber 65 around theimpeller and this small leakage will be stopped by the seal 70. The impeller blades 67 are generally turbine shaped, extending in planes atsubstantially right angles to the plane of rotation which issubstantially horizontal as shown in the figures.

Substantially centrally of each of the impeller blades 67 is a web orjoining member 71. I propose, for a purpose to be hereinafter explainedin detail, to make this joining structure 71 substantially asymmetrical,that is, between each two adjacent blades it slants down from one to theother, presenting in effect a differently shaped surface to fluids forone direction of rotation of impeller 68 than it does for the otherdirection of rotation of the impeller. Specifically, in the presentcase, each web member 71 is vformed as a right angle triangle having itsbase extending radially and connected to one blade 67, and its apexjoining the base of the adjacent blade.

Formed in the top wall 62 of pump 3% there are provided a pair of inlets72 and 73. While the inlet 72 is, as shown in FIGURE 4, formed simply bythe provision of an opening in the top wall, the inlet 73 includes achimney shaped member 74 extending upwardly from the opening in chamber65. This chimney member 74 may also be seen in FIGURE 1, which showsthat it extends upwardly into the tub 4 so as to be spaced a smallamount above the bottom of the tub. The chimney member 74 includes aflange 75 at its top which extends outwardly on the side toward opening72 so to extend to some degree over the opening 72. Both inlets 72 and73 lead, of course, into chamber 65, and it is contemplated that atleast a partial dam such as that shown at 76 is provided between the twoinlet openings although, as will be more fully explained herebelow,under some circumstances the dam 76 may be dispensed with. Preferably,as shown, the distance through chamber 65 from inlet 72 to itsassociated outlet 33 is greater than the distance from inlet 73 tooutlet 32. Because of :the well known characteristics of turbine pumps,this causes greater flow and pressure of liquid travelling the longerpath.

Completing the description of the pump structure of FIGURES 2., 3 and 4,the outlets 32 and 3 3 have secured therewi-thin respectively checkvalve members 77 and 78 to permit substantially unimpeded flow outthrough the outlets, and to prevent any backflow from the outlets intothe pump.

During operation of the machine 1, the pump impeller 68, as viewed inFIGURE 2, is turned in a clockwise direction during agitation operationsand in a counter clockwise direction during centrifuging openations. Asa result of the clockwise rotation during agitation, liquid is drawn inthrough inlet 73, and then pumped around to outlet 32, the liquid beingdiverted by the dam 66 into the outlet. Because of partial dam 76,virtually no liquid is drawn in through inlet 72, and this elfect may befurther increased by enlarging the inlet 73 to a substantial extent overthe size of the inlet 72. In fact, when the inlet 73 is substantiallylarger than inlet 72, as shown, it is possible to dispense entirely withthe dam 76 between the two inlets, and virtually all flow into the pumpwill occur through the inlet 73 during clockwise rotation thereof.

Referring back to FIGURE 1, it will readily be seen that flow outthrough outlet 32 is recirculated by being passed through nozzle 36 intofilter pan 37 and then back into the tub 4. Thus, the pump effects therecircula tion function during agitation. When the direction of the pumpis reversed, the pump draws in liquid through inlet 72 and passes it outthrough outlet 33.

It will be understood that if an adequate dam '75 is provided, the inletflow occurs only through inlet 72 at this time, but if the dam has beensubstantially eliminated then the inlet flow will occur through bothinlets 72 and 7-3, with the liquid then passing out through outlet 33 todrain as previously explained. In connection with this counterclockwisehow, and the shape of the impeller web members 71, it has been foundthat a substantial increase in the pressure and flow for one directionof the pump may be obtained by notching the joining web 71, as shown,rather than having it extend from the outer tip of one of the blades 67to the outer tip of the next blade as is conventional. Although it mightbe expected that notching the web 71 in the manner shown would tend toincrease flow with the impeller rotating in the clockwise direction, theresult is exactly the converse, the improved results being obtained forrotation in the counterclockwise direction.

Effective operation in both directions of rotation of the pump isobtained with no air locking. By locating the inlet in the top wall,rather than as conventionally done in the side wall, all air within thechamber 65 will inherently tend to bubble up through the unused inletand thus escape. Thus, even if there is air in the chamber, it can bepassed out through the inlet not being used. In addition, the entry ofair into the chamber may be decreased to a minimum by the provision ofthe check valves 77 and 78 so that the outlet which is experiencingsuction (outlet 32 during counterclockwise rotation and outlet 33 duringclockwise rotation) will not be caused to have air drawn through it intothe impeller chamber 65. Thus, my improved structure pumps eifectivelyin both directions of rotation with the air locking problem beinginherently eliminated by the pump structure.

A further advantageous feature of the struclufe described lies in theprovision of the chimney 74 surmounting the inlet 73. It will berecalled that the inlet 73 is used during recirculation. Duringrecirculation, it is not desired to recirculate sand and other heavysoils which during the washing operation tend to sink to the bottom ofthe tub 4. The chimney structure 74 tends to cause water to be taken inat a level above the heavy concentration of these soils so that only aminimal amount of such soils is passed through with the recirculatingwater, the major part of them sinking down below the top of the chimney74 and not being drawn into the pump until substantial suction occurs atinlet 72; they are then flushed out through the pump and down the drainas desired.

The flange at the top of chimney 74 has the benefiical elfects ofpreventing any vortex from being formed above inlet 72 during drainingoperations. The circular motion of impeller 68 tends to create such avortex, and when the liquid level is decreased during draining, thepresence of the vortex would cause entry of air into the pump chamber,thereby impairing pump operation. Flange 75 breaks up the circular flowpattern above inlet 72 and thus prevents the undesired vortex fromforming.

It will thus readily be seen that a number of highly advantageous anddesirable features are incorporated in the pump structure disclosed inFIGURES 2 through 4 and in its inclusion in the machine of FIGURE 1.

While in accordance with the patent statutes 1 have described what atpresent is considered to be the preferred embodiment of my invention, itwill be obvious to those skilled in the art that various changes andmodifications may be made therein without departing from the invention,and it is therefore aimed in the appended claims to cover all suchchanges and modifications as fall within the true spirit and scope of myinvention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A turbine pump comprising a housing having a substantially annularouter wall and top and bottom walls closing the ends of said outer wall,said housing defining therewithin a pump chamber, a rotatable impellerhaving an annular series of blades extending outwardly into said chamberand forming with said walls a substantially toroidal space, said outerwall having first and second circumferentially spaced outlet openingsformed therein, check valve means positioned to permit flow from saidchamber through said outlet openings and to prevent flow from saidoutlet openings into said chamber, said top wall having first and secondcircumferentially spaced inlet openings formed therein incircumferentially spaced relation to said first and second ouletopenings respectively, said inlet openings both opening into saidtoroidal space, and dams positioned respectively in said chamber betweensaid inlet openings and between said outlet openings.

2. The apparatus defined in claim 1 wherein said inlet openings aresubstantially adjacent each other.

3. A turbine pump comprising a housing having a substantially annularouter wall and top and bottom walls closing the ends of said outer wall,said housing defining therewithin a pump chamber, a rotatable impellerhaving an annular series of blades extending outwardly into said chamberand forming with said Walls a substantially toroidal space, said outerwall having first and second circumferentially spaced outlet openingsformed therein, check valve means positioned to permit flow from saidchamber through said outlet openings and to prevent flow from saidoutlet openings into said chamber, said top wall having first and secondcircumterentially spaced inlet openings formed therein incircumferentially spaced relation to said first and second outletopenings respectively, said inlet openings extending into communicationwith said toroidal space, and a dam positioned in said chamber betweensaid outlet openings, one of said inlet 8 openings having connectedthereto and extending upwardly a chimney member having its openingsubstantially above the other end of said inlet openings.

4. A turbine pump comprising a housing having a substantially annularouter wall and top and bottom walls closing the ends of said outer wall,said housing defining therewithin a pump chamber, a rotatable impellerhaving an annular series of blades extending outwardly into said chamberand forming with said Walls a substantially toroidal space, said outerwall having first and second circumferentially spaced outlet openingsformed therein, check valve means positioned to permit flow from saidchamber through said outlet openings and to prevent flow from saidoutlet openings into said chamber, said top wall having first and secondcircumferentially spaced inlet openings formed therein incircumferentially spaced relation to said first and second outletopenings respectively, and a dam positioned in said chamber between saidoutlet openings, said inlet openings both extending into communicationwith said toroidal space, one of said inlet openings being substantiallylarger than the other of said inlet openings whereby upon rotation ofsaid impeller in one direction liquid enters only through one inletopening and upon rotation of said impeller in the other direction theliquid tends to enter through both said inlet openings.

References Cited in the file of this patent UNITED STATES PATENTS1,380,798 Hansen et a1. June 7, 1921 1,475,676 Bell et al Nov. 27, 19232,746,391 Jaworowski et a1 May 22, 1956 2,838,002 Cohen June 10, 19582,862,452 Lung Dec. 2, 1958 2,864,312 Shelton et al. Dec. 16, 19582,883,843 Bochan Apr. 28, 1959 2,916,997 Terrie Dec. 15, 1959 2,923,144Smith Feb. 2, 1960 2,946,286 Sholtes et al. July 26, 1960 2,963,270Magarian Dec. 6, 1960 2,969,739 Clearman Jan. 31, 1961 3,018,650 SchmidtJan. 30, 1962 3,040,663 Cushing June 26, 1962 FOREIGN PATENTS 1,142,593France Apr. 1, 1957 UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No, 3, 127,840 April 7, 1964 John Bochan It is herebycertified that error appears in the above numbered patent requiringcorrection and that the said Letters Patent should read as correctedbelow.

Column 8, line 3, Strike out "end",

Signed and sealed this 28th day of July 1964,

(SEAL) Attest:

ESTON G. JOHNSON EDWARD J. BRENNER Attesting Officer I Commissioner ofPatents

1. A TURBINE PUMP COMPRISING A HOUSING HAVING A SUBSTANTIALLY ANNULAROUTER WALL AND TOP AND BOTTOM WALLS CLOSING THE ENDS OF SAID OUTER WALL,SAID HOUSING DEFINING THEREWITHIN A PUMP CHAMBER, A ROTABLE IMPELLERHABING AN ANNULAR SERIES OF BLADES EXTENDING OUTWARDLY INTO SAID CHAMBERAND FORMING WITH SAID WALLS A SUBSTANTIALLY TOROIDAL SPACE, SAID OUTERWALL HAVING FIRST AND SECOND CIRCUMFERENTIALLY SPACED OUTLET OPENINGSFORMED THEREIN, CHECK VALVE MEANS POSITIONED TO PERMIT FLOW FROM SAIDCHAMBER THROUGH SAID OUTLET OPENINGS AND TO PREVENT FLOW